It doesn't appear to be all that rare. This was the first article that came up when I Googled the subject.
Once you apply for the card and your application is approved, oftentimes the company will simply assume payment responsibilities from there. This can work out to become a strong business relationship, but the fact remains that applying for the card (at the company's request) does produce an inquiry on your credit report — a standard inquiry, because you are applying for a new card — but it is still an inquiry on your credit history, and it could one day affect your credit score.